Performance improvements of polarization analyzing CMOS image sensor using multiple pixel array architecture and 65nm standard CMOS process

We have been developing polarization-analyzing CMOS image sensor with monolithically embedded polarizer [1, 2]. Differing from preceding works [3-5], we implement on-chip polarizers configured with a metal wiring layer available in standard CMOS technology. In the last workshop, we have demonstrated the polarization-analyzing functionality with a CMOS image sensor fabricated with 0.35 μm standard CMOS process. Figure 1 schematically shows the concept of polarization-analyzing pixel. We implemented an on-chip polarizer configured with metal wire structures. Owing to the on-chip polarizer, the pixel shows polarization-dependent sensitivity [1, 2]. The typical extinction ratio of the on-chip polarizer was 6.7 for line / space = 0.5 μm / 0.45 μm [1], and 2.03 for line / space = 0.6 μm / 0.6 μm [2].